Rf generator with multiplexed programmed molds

ABSTRACT

Each platform mounted mold assembly for plastic tubing includes a circuit board containing parameters defining elements of the forming, molding, tipping or welding operation to be undertaken on the tubing. A control unit includes an RF generator for providing the RF energy to effect the forming, molding, tipping or welding process, a source of air under pressure to operate the mechanical elements attendant each mold assembly, various sensors and a multiplex unit. In operation, the control unit serially addresses each of the mold assemblies, senses the parameters attendant the mold and applies the appropriate power level of RF energy for a specific duration and temperature while activating the mechanical aspects of the mold assembly. The mold assemblies may be serially activated through a multiplex unit or in a particular sequence that may be operator controlled.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application relates to and incorporates by reference hereinthe subject matter disclosed in provisional application entitled “RFGENERATOR WITH MULTIPLE MOLDS”, Ser. No. 61/148,861, filed Jan. 30,2009, which application is assigned to the present assignee.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to forming, molding, tipping and weldingplastic tubing and, more particularly, to molds having data incorporatedin a circuit for controlling the operation of an RF generator to heat,form, mold, tip and weld the tubing within the mold and including amultiplexing capability for interconnecting a plurality of such moldswith a single RF generator and controller or computer.

2. Description of Related Prior Art

Molds forming, molding, tipping and welding plastic tubing are connectedto a source for producing an electrical signal to heat the mold andthereby cause the forming, molding, tipping or welding of plasticmaterial, such as tubing. Heating of the mold may be by resistanceheating or inductive heating as the most common forms. In the lattercase, radio frequency (RF) energy is employed and an RF generator iselectrically connected to the mold to provide the requisite energysource. For different molds or molds having differing capabilities andfunctions, the electrical signal applied must be tailored or otherwiseadapted within the RF generator to ensure proper and successful forming,molding, tipping and/or welding of the tubing. This procedure has thepossibility of inadvertently resulting in operator error. That is, anoperator may inadvertently enter incorrect parameters into the controlcircuit for the RF generator. As a result, the forming, welding, tippingor welding of the plastic tubing will not occur as intended. Sometimes,presumably identical molds are in fact not identical due tomanufacturing errors or operator fault. In either case, the parameterspreset in the RF generator will not produce the desired function on theplastic tubing.

Presently, each mold requires its own RF generator which results invarious less than preferred situations. The use of a single mold with asingle RF generator requires an operator between each operation to loadthe mold with the plastic tubing and after the operation to unload thetubing from the mold. Where a rapid throughput is required or stronglypreferred, the time involved for such loading and unloading between eachoperation has a negative impact on the throughput. The use of a singleRF generator to energize a single mold requires significant capitalexpense when a plurality of molds are required by production criteria.That is, the costs of the mold and the RF generator are significant andresult in a significant cost per operation of forming, molding, tippingand/or welding the tubing.

In summary, the current practice is to manually enter the settings intoa control module, such as a computer, at the time of installation of thetooling/mold or enter settings in advance and select the appropriatesettings at the time of use. In most controlled manufacturing plants,different individuals originate and validate the proper settings for agiven operation on a mold than the personnel who use the mold routinelyin production. The correct use requires production personnel toduplicate the setting procedure. This takes time and is a potentialsource of error. Accordingly, a method that would save time and ensureaccuracy of the settings is sought.

SUMMARY OF THE INVENTION

The present invention includes a single RF generator for generating RFenergy to heat a mold and form, mold, tip and/or weld plastic tubingdisposed in the mold in a mold assembly. Each mold assembly includes acircuit board electrically connected to the RF generator and/or acontroller therefor for providing control signals to the RF generator toproduce actuating signals for the mold commensurate with the parametersof the mold. No operator input is required. To enhance the efficiency ofuse of the RF generator, a multiplexing circuit may be incorporated toserially or in a specified order energize each of the molds pursuant tothe parameters of each mold as reflected in its control signals.

An electrically shielded module containing an electronic assembly with asemiconductor memory device and a semiconductor identification device ispart of the mold assembly. Signals to and from the module or circuitboard are routed through conductors along with the temperature sensingand heating power conductors through interconnections between the moldassembly and the supporting electromechanical platform. From theplatform, the signals are conducted to the RF generator/computer. Withappropriate software/programming, the computer is enabled toautomatically load the settings from the memory and use them to controlthe heating, cooling, motion and other functions. These settings mayhave been previously determined to be correct by appropriate individualsand loaded into the memory. Thereafter, the routine use of the mold byproduction personnel is facilitated by not having to re-enter thesettings and the control/accuracy is assured. In locations where manydifferent products are made, the savings in time and reduction in badproduct due to incorrect equipment settings may be substantial. Qualitysystem requirements at manufacturing facilities involving documentationand controls may be improved by better control of the settings for theapparatus. If the computer is additionally programmed to output or logdata for each use, the identification and settings will provide furtherbenefits. When the mold assembly with memory and I.D. apparatus are usedwith a plurality of platforms simultaneously connected to one RFgenerator that is suitably equipped with switching means, such as amultiplexer, and software, the computer can automatically load thesettings from each mold and then execute the control sequence for eachmolding operation with the corresponding settings as each platform/moldis used. Multiple parts with different settings may than be made withone RF generator/computer with one or more operators, resulting indecreased costs and improved process control. If suitably programmed andequipped with data output (logging) devices, the I.D. (or otherreference stored in the memory of each mold assembly) may be enteredinto the record output by the RF generator/computer, with each moldingoperation's information interleaved with the other molds' records.

It is therefore a primary object of the present invention to provide amold assembly having unique parameters of operation translated intocontrol signals for an RF generator to actuate the operation of the moldassembly in conformance with such control signals.

Another object of the present invention is to provide a multiplexingcapability for a single RF generator to serially actuate each of aplurality of mold assemblies.

Still another object of the present invention is to provide thecapability for interconnecting a plurality of different mold assemblieswith a single RF generator and control the operation of each moldassembly in conformance with control signals produced by each moldassembly.

Yet another object of the present invention is to provide a multiplexingcapability for interconnecting and energizing each of a plurality ofmold assemblies with a single RF generator.

A further object of the present invention is to provide a mold assemblyhaving a circuit board for providing control signals to a connected RFgenerator for controlling the actuating signal from the RF generator tothe mold assembly.

A still further object of the present invention is to provide apparatusfor eliminating the requirement for an operator to enter control signalsinto an RF generator to provide the requisite electrical energy to amold assembly.

A yet further object of the present invention is to provide a method forhaving a mold assembly, energized by an RF generator, control thesignals generated by the RF generator for energizing the mold assembly.

These and other objects of the present invention will become apparent tothose skilled in the art and the description thereof proceeds.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be described with greater specificity andclarity with reference to the following drawing, in which:

FIG. 1 is a system diagram of the components of the present inventionand the interconnections therebetween;

FIG. 2 illustrates the function and operation of a multiplexing unitinterconnecting an RF generator and associated computer/controller witheach of a plurality of mold platforms;

FIG. 3 is a representative view of a commercial pressure regulator forcontrolling the air pressure applied to each respective mold platform;

FIG. 4 is a representative drawing illustrating optional sequencing forenergizing some or all of the mold platforms;

FIG. 5 is a circuit diagram illustrating an interconnection between themultiplexer and the control circuit in each mold platform delivering theparameters of such mold;

FIG. 6 illustrates a circuit for identifying the molds to be energized;

FIG. 7 is a representation of a memory integrated circuit;

FIG. 8 illustrates an exploded view of the mold and the mold assembly;

FIG. 9 illustrates the mold assembly mounted on a platform for insertingand withdrawing tubing to be acted upon by the mold and mold assembly;

FIG. 10 illustrates the mold housing attached to a substrate within theplatform;

FIG. 11 illustrates the mold assembly and electrical connectors of theplatform connectable to PC boards of the mold assembly;

FIG. 12 illustrates the mold assembly attached to press-in connectors;

FIG. 13 is a further view illustrating the electrical connectorsattachable to the mold assembly;

FIG. 14 is a further illustration of the location of the mold assemblyand its electrical connectors relative to a substrate of the platform;and

FIG. 15 is a side view of the components shown in FIG. 14.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The purposes and functions of the present invention are directed to twoprimary features. First, a multiplexer is incorporated to reduce theoverall system cost by sharing expensive components between numerousless expensive elements. Previously, every mold assembly supportingplatform, which is a relatively low-cost component, had to be joined toa dedicated RF generator, a high-cost component. To increasefunctionality and reduce overall costs of the equipment, the presentinvention allows leveraging the high-cost component, the RF generator,with multiple mold assembly supporting platforms. A multiplexer is usedto provide this function whereby each of the mold assembly supportingplatforms has access to the shared component, the RF generator. The useof a multiplexer provides serial access between each mold assemblysupporting platform and the RF generator in the nature of time sharing.

A second feature of the present invention relates to the input to acomputer controlled RF generator of the parameters of a particularplatform mounted mold assembly to obtain the requisite forming, molding,tipping or welding of the plastic material, which may be plastic tubing,to be acted upon. Presently, such parameters are manually entered into acomputer controlling operation of the RF generator. While this procedureis adequate, operator errors may occur through incorrect settings.Furthermore, as each mold may have different parameters as a function ofthe forming, molding, tipping or welding to be accomplished, thesettings for a previously used mold assembly may be inadvertently notchanged. Additionally, as throughput is always an important function inany manufacturing process, significant delays may result from therequirement of operator input of settings for each mold assembly. Byincorporating a control circuit, such as a PC board or memory chip, ineach mold assembly, it can be programmed to contain the parameters ofthe mold. Upon interrogation of the control circuit by a computer, therequired settings for the RF generator will be automaticallyestablished. This avoids potential operator error, reduces set-up timeand facilitates changing of mold assemblies and attendant automaticresetting of the RF generator to provide the requisite RF generatoroperation.

Referring to FIG. 1 there is a detailed system diagram illustrating thepreferred embodiment of the present invention. It includes RF generator10, temperature and motion control circuitry attendant each mold andmold platform, an HMI touch screen 12 and a computer 14. Each platform20, 22, 24 and 26 supports a mold assembly including a mold 28, 30, 32and 34 and a trigger or switch 36, 38, 40 and 42, respectively. Amultiplexer 44 serially interconnects the mold assemblies and molds 28,30, 32 and 34 with the RF generator, as well as various other functionsto be performed.

FIG. 2 is a simplified block diagram of the system shown in FIG. 1. Eachmold assembly is mounted on one of platforms 1, 2, 3 or 4. Each moldassembly includes a control circuit to provide electrical signalscorresponding with the unique parameters of the mold. These signals aretransmitted to multiplexer 44 via the electrical conductors identifiedas mold code. The mold code is transmitted via electrical conductor 46to computer 14. The computer controls operation of the RF circuitrepresented by RF generator 48. A source 50 of air under pressure,identified as “shop-air”, conveys through tubing 52 air under pressureto pressure regulators 54. The pressure regulators, under control of thecomputer through a conductor identified as pressure control in responseto a signal conveyed to the computer through a conductor identified aspressure sense causes an outflow of air under pressure from the pressureregulators is interconnected by one manifold with the molds and fixtureson each of platforms 1, 2, 3 and 4. As illustrated, a foot switch may beassociated with each of the platforms and operation of the respectivefoot switch is conveyed through the multiplexer to computer 14 by theconduits identified as key 1, key 2, key 3 and key 4. Additionally,temperature sensing and control attendant each of the molds is conveyedthrough conductors identified by the term temperature and correspondingwith each respective mold. When a foot switch attendant one of theplatforms is closed, a signal is sent to the computer. Once the computerreceives the signal it then sends a specific platform select signal anda pressure control signal to the multiplexer. The multiplexer thenconnects the RF generator, pneumatic valves and temperature sensingsignals for use in temperature and motion control to the triggeredplatform and disconnects the signals from the other platforms. Forexample, if the switch located on platform 1 is closed, the computersenses that platform 1 has been activated. The computer then signals themultiplexer to connect a thermocouple, RF conductor and motion controllines to platform 1 to the RF generator. The computer then signals thepressure control modules, which may be located in the multiplexer, tochange to the appropriate pressure for platform 1. All of the platformsshare a common pressure source.

Referring to FIG. 3, there is shown an off-the-shelf digital pressureregulator 54 manufactured by SMC. Two of these regulators may be presentin the multiplexer. They receive different signals from the RF generatordepending on the setting for the particular platform to be activated.They adjust to pressure proportionately to the signal they receive(0-5v). The resulting pressure is relative to the platforms and may becontinually shared.

FIG. 4 illustrates the sequential nature of multiplexing that may beentertained in the present invention. Presently, the apparatus has twoconstraints unique to the apparatus:

1. The RF generator has a duty cycle constraint of approximately 50% tomaintain a relatively small size cabinet and acceptable weight withoutfurther heat sink devices, fans, etc.;

2. The number of input/output lines available and the simultaneousprocessing tasks/times that can be handled by the controller areinitially set by a known multiplexing apparatus. To maintain theenclosure size, power supply limits, heat generation, etc. thecontroller input/output lines are switched in the multiplexer and theprocess logic for the individual molds/platforms is run sequentially.

Presently there are three types of queuing modes:

1. Mode 1 configures a system for a “next up” scenario. In anenvironment where each platform has an operator, the RF generator willonly recognize triggers when it is in an idle state (not providingsignals to the platform). Whichever platform is triggered will thenimmediately begin to operate. For example, if the cycle for platformnumber 2 has just ended, and if someone now triggers platform number 3it will begin to operate.

2. Mode 2 configures the system for a “first come, first served” or“take a number” operation. In an environment where each platform mayhave an operator, the RF generator will monitor triggers (foot switchesillustrated in FIG. 2) even when it is not in an idle state. Forexample, if platform number 2 is running and platform number 3 istriggered before the cycle finishes, the RF generator will operateplatform number 3 as soon as operation on platform number 2 hasterminated.

3. Mode 3 allows the operator to set up a predefined order in which theplatforms will be operated. By triggering (foot switch actuation) anyone of the platforms will cause a sequence of operation to begin. Forexample, if the order of operation of the platforms is intended to be 1,3, 4 and 2, and platform number 3 is triggered, the RF generator willcause operation of platforms number 1, 3, 4 and 2. This mode is commonlyused in an environment where a single operator is operating severalplatforms.

Most molds used to form, mold, tip or weld plastic material, such asplastic tubing, require a unique set of parameters in order to performthe intended function. The parameters are simply settings used tooperate the mold, mold assembly and the platform correctly for aparticular application. Though the parameters may be unique for anygiven mold, the type of information stored remains constant. Forexample, the parameters include temperature, heat time, cool time andpressure, to name a few. Sometimes changing these in the RF generator(or an associated computer) every time a mold is changed is not onlycumbersome but fraught with the possibility of erroneous entries. Thisis exacerbated by the fact that there may be up to 30 differentparameters for each mold and the likelihood of operator mistake is high.One way of overcoming potential operator error is to store theparameters in the RF generator/computer. For a limited number ofdifferent molds, this may be practical but when there is a possibilityof using 100 or more molds, the information to be stored in the RFgenerator/computer is far too vast. In addition, any repair work on theRF generator/computer creates a risk of changes to the stored parametersor even loss of some or all of the parameters. To prevent suchpotentially disastrous result, all of the parameters would have to berecorded and possibly reentered on completion of the repairs. Such workwould necessarily delay return to service of the equipment and give riseto the possibility of misentry of some parameters.

By storing the information attendant a mold in the mold assembly itselfand having the RF generator/computer interrogate the mold as to itsunique parameters, any need for storing the parameters other than in amold assembly is completely avoided. Moreover, during manufacture of amold to perform a particular forming, molding, tipping or weldingfunction on plastic material, whether plastic tubing or otherwise, theattendant parameters are determinable and a circuit board, memory chipor other interrogatable data source formed as part of or attached to themold assembly renders the mold ready for use on receipt by the user.These features are representatively illustrated in FIGS. 5 and 6. FIG. 7is a representative illustration of a presently available conventionalmemory integrated circuit 56 that could be programmed to contain therespective parameters. Moreover, the memory integrated circuit can bereadily interrogated to provide the parameters attendant operation ofthe associated mold. A circuit board supporting the requisiteinformation containing components could similarly be associated with orotherwise attached to each mold assembly.

In particular, FIG. 5 illustrates a voltage divider 58 located withinthe multiplexer electronic assembly 44. It is shown with nodes 60between resistors R that are connected to the connectors (ports) throughwhich control signals are passed to each of the platforms. Theconnections are such that the applied voltage (which may be +5 vdc)divided by five is connected to a platform number signal pin in theconnector to attach platform number 1. The corresponding pin in thesecond platform's connector (platform number signal) is connected to thenext higher divider node; that is, 2× V/5. If V+ is 5 vdc then theplatform number signal for platform number 1 is 1 vdc, platform number 2is 2 vdc, platform number 3 is 3 vdc and platform number 4 is 4 vdc. Theright hand side of FIG. 5 illustrates these connections for platformsnumbers 2 and 4. It also shows the electrical connections connected tothe memory ID symbol number circuit 62 within the mold assembly andmemory containing assembly 64. This mold assembly is mechanicallyattached and electrically connected to a platform. Two such platformsare shown in FIG. 5 along with the mold assemblies connected to ports 2and 4.

An additional connection is shown to each mold and platform assemblywhich is in turn connected to the others and then to the multiplexer.This additional connection is the “1-wire bus” signal. The 1-wirenetwork protocol is a serial bus connection. All devices share 1-wireand each device node has a unique network address on that bus. It isnecessary for the operation of this apparatus that the mold/memory beassociated with the platform within which it is physically located inorder to properly apply the control signals to that platform and theassociated task.

FIG. 6 details the memory ID number circuit within the mold assembly. Asecond voltage divider 66 similar to the one shown in FIG. 5 isconnected to a “quad comparator” (such as a LM339) device 68 invertinginputs as references for V/5, 2×V/5, etc. and the platform number signalis simultaneously connected to the non-inverting inputs of allcomparators. In practice, the resistor values have slightly changed fromthe multiplex divider (58 FIG. 5) such that the resistor closest toground in the platform is somewhat smaller than its counterpart to allowa margin for noise. Thus, with 1 vdc coming from the multiplexerplatform number 1 connector, the reference at the V/5 comparator wouldbe set to 1-0.2 vdc. The outputs of the four comparators are routed tothe least significant four address inputs of the DS28E04-100 memorydevice 69 (4096 bit 1-wire EEPROM, Dallas Semiconductor). Referring tothe truth table, if the platform number signal is less than the voltagerequired to turn on the first comparator, then all address lines are 0.If the signal is 1 vdc, then the result is a logical 0001. If thevoltage is 4 vdc then all four bits are set. These bits are contained inthe 64-bit device I.D. that may be read over the 1-wire network. By thismeans, the 1-wire network device discovery protocol software run in thegenerator/controller may associate the physical location within eachplatform for each of the memories found.

A preferred embodiment of mold assembly is illustrated in FIG. 8-13.Certain details of this mold assembly relating to the structure andoperation is set forth in U.S. Pat. No. 7,438,548 entitled “APPARATUSFOR RAPIDLY HEATING AND COOLING A CATHETER MOLD”, filed Oct. 31, 2006,which is assigned to the present assignee. The substance of theinformation contained in this patent is incorporated herein byreference.

FIG. 8 is an exploded view of mold assembly 70 and various componentsare functionally labeled. This particular mold assembly may be used forforming, molding, tipping and/or welding plastic tubing. FIG. 9illustrates a platform 72 for supporting mold assembly 70 and thefixtures 74, 76 for inserting and withdrawing the plastic tubing fromthe mold assembly. The mold itself, identified by number 78 in FIG. 8,is disposed within the mold assembly. To remove mold assembly 70 inorder to substitute another mold assembly having a different mold, themold assembly may be withdrawn by raising it relative to platform 72.

Referring jointly to FIGS. 10-15, details attendant the mechanical andelectrical interconnection between mold assembly 70 and the platform 72will be described. A substrate 74 is disposed within the platform. Thesubstrate mechanically supports a pair of female electrical connectors76, 78 mounted on a plate 80. A bracket 82 extending downwardly fromsubstrate 74, as particularly shown in FIG. 15 for supporting plate 80.Mold assembly 70 is inserted through opening 84 in substrate 74, asshown in FIG. 14. Upon such insertion, contacts attendant printedcircuit board 86 engage electrical connector 78. Contacts attendantcircuit board 88 electrically engage electrical connector 76. Asillustrated, guide pins 90, 92 may be incorporated to ensure accuratealignment with the electrical connectors. Printed circuit board 88,identified as “Smart Mold PCBA” contains the parameters attendantoperation of the mold. These parameters are transmitted via electricalconnector 76 to the above discussed computer and RF generator.Additionally, printed circuit board 86 includes data attendant operationof the mold as a function of the RF generator. In particular, printedcircuit board 86 includes data attendant operation of the mold as afunction of the RF generator. In particular, printed circuit board 86includes information for tuning the heater located within the moldassembly that ultimately heats the mold. Moreover, the RF energy to beapplied may be transmitted through this printed circuit board.

As shown in FIG. 1, the HMI (human machine interface), which is commonin the industry, is used to display real time mold temperature,settings, graphical representation of the temperature versus time aswell as identifying LEDs showing which processes are currently inoperation. Other information unique to the operation under way or themold, etc. may displayed to an operator.

1. Apparatus for molding, forming, tipping and/or welding plasticmaterial, said apparatus comprising in combination: a) an RF generatorfor providing an RF signal; b) at least one mold assembly responsive tothe RF signal for molding, forming, tipping and/or welding the plasticmaterial in a mold; and c) a control circuit disposed in conjunctionwith each of said at least one mold assembly for providing controlsignals to said RF generator to produce the RF signal unique to theparameters of said mold in said at least one mold assembly.
 2. Theapparatus as set forth in claim 1 including a plurality of moldassemblies interconnected with said RF generator and a multiplexingcircuit for serially interconnecting each mold of said plurality of moldassemblies with said RF generator.
 3. The apparatus as set forth inclaim 1 wherein the plastic material is plastic tubing and including aplatform for supporting one mold assembly of said at least one moldassembly and fixtures mounted on each of said platforms for insertingthe plastic tubing into said mold and withdrawing the plastic tubingfrom said mold.
 4. The apparatus as set forth in claim 3 including aplurality of mold assemblies and a multiplexing circuit for seriallyinterconnecting each mold assembly of said plurality of mold assemblieswith said RF generator.
 5. The apparatus as set forth in claim 1 whereinsaid at least one mold assembly comprises a plurality of mold assembliesand a plurality of platforms, each of said platforms supporting one ofsaid mold assemblies.
 6. The apparatus as set forth in claim 5 whereinthe plastic material comprises plastic tubing and wherein each platformof said plurality of platforms includes fixtures mounted thereon forinserting the plastic tubing into the respective mold and forwithdrawing the plastic tubing from the respective mold.
 7. Theapparatus as set forth in claim 6 including a source of air underpressure for actuating said fixtures in response to the control signals.8. The apparatus as set forth in claim 7 including a computer/controllerdisposed with said RF generator responsive to the control signals fromsaid control circuit for controlling operation of said RF generator,said mold assemblies and said fixtures mounted on each platform of saidplurality of platforms.
 9. The apparatus as set forth in claim 1 whereinsaid control circuit is a conventional memory integrated circuit mountedin each mold assembly of said at least one mold assembly.
 10. Theapparatus as set forth in claim 9 including a platform for detachablysupporting said at least one mold assembly and electrical connectionsfor electrically connecting said control circuit with said RF generator.11. The apparatus as set forth in claim 10 including a plurality ofplatforms, each of said platforms supporting a mold assembly of said atleast one mold assembly, a multiplexer for serially interconnecting eachof said mold assemblies with said RF generator to serially actuate andenergize each of said molds.
 12. The apparatus as set forth in claim 10including fixtures mounted on each of said platforms for engaging anddisengaging the plastic material with said mold assembly and a source ofair under pressure for actuating said fixtures.
 13. A method forforming, molding, tipping and/or welding plastic material in a mold,said method comprising the steps of: a) generating an RF signal with anRF generator; b) forming, molding, tipping and/or welding the plasticmaterial in at least one mold assembly supporting the mold; and c)providing a control signal from each of the mold assemblies to the RFgenerator, which signal is reflective of the parameters of therespective mold to control operation of the RF generator.
 14. A methodas set forth in claim 13 including a computer/controller and the step ofproviding the control signals to the computer for controlling operationof the RF generator.
 15. A method as set forth in claim 14 wherein theplastic material is plastic tubing, each mold assembly being mounted ona platform and including fixtures for inserting and withdrawing theplastic tubing from the mold and the step of regulating operation of thefixtures with signals from the computer.
 16. A method as set forth inclaim 15 including a source of air under pressure and the step ofchanneling air to actuate the fixtures and to cool the mold in responseto signals from the computer/controller.
 17. A method as set forth inclaim 13 including the step of mounting a control circuit in each moldassembly to provide control signals unique to the parameters of therespective mold.
 18. A method as set forth in claim 17 wherein saidmounting step includes the step of detachably attaching a memoryintegrated circuit.
 19. A method as set forth in claim 18 including aplatform for supporting the mold assembly and the step of removablymounting the mold assembly on a substrate of the platform.
 20. A methodas set forth in claim 19 including the step of interchanging differentmold assemblies on the platform.
 21. A method as set forth in claim 20wherein a plurality of mold assemblies are mounted on respectiveplatforms and including the step of serially controlling the operationof each mold assembly and its associated fixtures through a multiplexerreceiving mold dependent signals from the RF generator and thecomputer/controller.
 22. Apparatus for forming, welding and tippingplastic tubing, said apparatus comprising in combination: a) a generatorfor providing a source of RF energy; b) a platform; c) a mold assemblymounted on said platform and including a mold for forming, welding ortipping the plastic tubing; and d) a control circuit incorporated aspart of said mold assembly for controlling operation of said generatorto apply RF energy to the plastic tubing within said mold.
 23. Theapparatus as set forth in claim 22 including a plurality of saidplatforms and each of a plurality of said mold assemblies being locatedon one of said platforms and a multiplexer for distributing RF energyfrom said generator to each mold in said plurality of mold assemblies.